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<p>Reports errors in string formatting operations.</p>
<p><b>Example 1:</b></p>
<pre><code>
"Hello {1}".format("people")
</code></pre>
<p><b>Example 2:</b></p>
<pre><code>
def bar():
    return 1


"%s %s" % bar()
</code></pre>
<p>As a fix, you need to rewrite string formatting fragments to
  adhere to the <a href="https://docs.python.org/3/library/string.html#format-string-syntax">formatting syntax</a>.</p>
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